My brother worked for a help organization in africa for 1,5 years. When he came back, he told me that they throw food away too. I only cook as much as i can eat.
Even in my university's restaurant, which feeds students on a massive industrial scale, I see food waste. But even in a much bigger scale, the amount was significantly less.
Elimination of food waste is not practical and should not be a goal, you'll just ultimately fail and give up on intermediary goals that might just suffice.
Where the food usually goes are into landfills where they produce dangerous accumulations of methane that can explode. Some folks have tried capturing that methane to burn, but if stuff can be made into compost, you’d need less synthetic fertilizers.